Apparatus for dressing convex surfaces on grinding wheels



.uy l0, 1951 J, KLOPA'K' 2,560,454

APPARATUS FOR DRESSING CNVEX SURFACES ON' GRINDING WHEELS Filed April e,1949 lllll I|| .K1 5MM rma@ m VH T NwM/A S www B Patented July 10, 1951APPARATUS FOR DRESSING CONVEX SUR- FACES N GRINDING WHEELS JosephKlopak, Newark, N. J., assigner Ato Gen eral Motors Corporation,Detroit, Mich., a corporation of Delaware Application April 8, 1949,Serial No. 86,254

Claims. (Cl. 125g-11) This invention relates to apparatus for dressingconvex surfaces on grinding wheels, especially large radius curves onwheels of large diameter. In prior apparatus for dressing convex curves,the apparatus has been subject to vibration and, in order to get thecenter of curvature inside of the body of the Wheel, a large pivotedyoke has straddled a large portion of the wheel. This leads toundesirable bulk and expense.

An object of the invention, accordingly, is to provide a dressingapparatus which will avoid the above mentioned and other defects inprior devices. Another object is to provide.a compact but ruggeddressing apparatus which will dress any selected convex curve across theperiphery of a grinding wheel and be tree from vibration. Another objectis to provide improved apparatus for locating the center of curvatureabout which the dressing tool travels inside the body of the wheel withprovision for varying theradius of the curve produced without the needof a plurality of templates or formers.

In the drawings,

Fig. 1 is a plan View with a splash guard in section.

Fig. 2 is a view of parts of Fig. l in another position.

Fig. 3 is a perspective view of a blade and it follower,

Fig. 4 is a front view of Fig. 1.

Fig. 5 is a side view of Fig. 1 with a slide in section.

Fig. 6 is a plan view of a slide.

Fig. 7 is a perspective View of a gauge.

A main bracket 2 has a base flange 4 secured by screws 5 to the grindingwheel head. The bracket has a platform 8 on which is fastened adovetail' guiding tongue II] whose center is in line with the centralplane of the grinding wheel G. A slide I2 having guide rails isshiftable along the guide by a screw I4 threaded in a nut IB on theslide and journalled for rotation without endwise movement in a plate I8fastened to the platform. Fastened in a recess of the slide I2 is aprole blade or template 2B having an arcuate guiding edge 22 engaged bythe tip of a wedged shaped follower 24 formed on a stud 26 which securesthe follower to a swinging diamond carrying arm 28. The follower has aflange 3D extending under an overhanging portion of the blade to holdthe arm 2B down on the top of the plate l2. The follower and its angeare shiftable in an arcuate recess 32 of the slide I2. The enlargedfront of the arm 28 has a threaded recess to adjustably receive athreaded diamond holder 34 in which a headed stud carrying a cuttingtool or dressing diamond 36 is secured. A curved splash guard 38 havingan opening for the arm 2B is guided between curved angle plates fastenedon a main splash guard 40 which substantially iollows the outline of theslide I2.

The arm 23 is connected to a longer arm 42 by parallel links 44 and 46of equal length pivoted to each arm. The front end of the longer arm ispivoted to the slide I2 at one side of the wheel by a pivot stud 48which is connected by a coil spring 5I! to a stud on the link 46. Thespring holds the follower pressed against the profile blade. Pivoted tothe arm 42 is a link 52 which is in turn pivoted in the fork of a yoke54 adjust- .ably secured to one end of a piston rod 56 projecting from acylinder 58 secured to the slide I2.

The pistonand cylinder unit oscillates the Varrn 42 about its pivot 48and the parallel links cause the diamond carrying arm 28 to follow inparallelism. While this occurs the follower 24 is kept pressed againstthe prole blade thus controlling the motion of the diamond in an arc.The center of the curvature to be produced on the grinding wheel isinside the body of the wheel as indicated at C in Fig. 1; a planeperpendicular to the side ofthe grinding wheel through this point C willalso pass through the center of the pivot stud 4S. This condition ismaintained whatever the radius of the curvature to be produced. Thecurvature of the profile blade has the same center of curvature as Ythecurvature to be produced on the wheel but it has a larger radius.

Actuation of the screw I4 adjusts the slide I2 to locate the pivot 48 sothat the center C which corresponds to it will come at the desireddistance V from the periphery of the wheel. If a larger radius ofcurvature is desired, the slide I2 and its appurtenances are advancedtowards the wheel and the diamond holder 34 is adjusted away from thewheel by the same amount by turning it in its threaded recess. Theforegoing shifts the center C deeper into the wheel. If a smaller radiusof curvature is desired, the slide I2 and its appurtenances areretracted from the wheel and the diamond holder is advanced the sameamount. The prole blade serves as the guide for every radius desired.Its arcuate curvature is a known constant and its center of curvature isalways at the center of curvature to be produced. I'he radius of thecurvature to be produced is the distance from the diamond to the planethrough the pivot 48 perpendicular to the side of the wheel. Theapparatus is not limited to the dressing of arcuate curves. Other formscan be dressed by blades of the selected shapes.

Fig. 6 shows a set-up gauge 60 for accurate location of the diamondholder in the arm 28. The gauge (shown enlarged) will t around a portionof the diamond holder and when its arcuate edge 62 is placed against theend of the arm 28, the diamond holder can be shifted to make the diamondjust meet the bottom wall 64. The amount that the diamond projects fromthe arm 28 is then the known depth of the gauge. The distance of the endof the arm from the edge of the blade is a known constant.

Iclaim:

1. In apparatus for forming a convex curve across the periphery of agrinding wheel, a long arm pivoted at one side of the grinding wheel,the pivot lying in a plane intersecting the wheel at right angles, asecond and shorter arm normally in the central plane `of the grindingwheel, links pivotally connecting the arms in parallelism, a cuttingtool at one end of the shorter arm, a follower on the shorter arm, aconvex prole blade extending across the plane of the grinding wheel andhaving its center of curvature within the body of the wheel and in theaforementioned intersecting plane, a spring urging the follower againstthe blade, and means operatively connected to the longer arm foroscillating the longer arm around its pivot to traverse the followeralong the blade.

2. In apparatus for dressing a convex surface of revolution on agrinding wheel, a movable arm normally in the plane of the grindingwheel, a cutting tool at one end of the arm and engageable with thegrinding wheel, a prole blade having anrarcuate surface crossing theplane of the grinding wheel and having its center of curvature withinthe body of the grinding wheel, a follower on the arm and engaging saidarcuate surface on the profile blade, a spring urging the follower intoengagement with said arcuate surface, mechanism including a pivotedmember and pivoted parallel links holding the movable arm radially ofsaid arcuate surface and oscillating mechanism connected to said pivotedmember.

3. In apparatus for forming a convex curve across the periphery of agrinding wheel, a long arm pivoted at one side of the grinding Wheel, asecond and shorter arm beside the rst, links pivotally connecting thearms, a cutting tool at one end of the shorter arm and engageable withthe grinding wheel, a prole blade having a convexed surface extendingacross the plane of the wheel and having its center of curvature withinthe body of the wheel, oscillating mechanism operatively connected tothe longer arm for swinging said longer arm about its pivot, and afollower engaging the convexed blade surface for controlling the motionof the shorter arm.

4. In apparatus for forming a convex curve across the periphery of agrinding wheel, a slide, an arm pivoted to the slide at one side of thegrinding wheel, a second arm, parallel links pivotally connected to thearms, the slide having an arcuate slot, a prole blade secured t0 theslide and overhanging the slot, a follower secured to the second arm andentering the slot to ride along the blade, a cutting tool carried by thearm, oscillating mechanism connected to the rst mentioned arm, anadjustment member for shifting the slide towards and from the peripheryof the wheel to select the position of the center of oscillation, and anadjustable holder locating the cutting tool lengthwise of the secondarm.

5. In apparatus for forming a convex curve across the periphery of agrinding wheel, a slide, an arm pivoted to the slide at one side of thegrinding wheel, a second arm, parallel links pivotally connected to thearms, a profile blade secured to the slide and having an arcuate surfacecrossing the plane of the grinding wheel, a follower secured to thesecond arm and urged against the blade, a cutting tool adjustablysecured to the second arm, mechanism operatively connected to one ofsaid arms for oscillating the rst mentioned arm to cause the follower totraverse said arcuate surface, and feeding mechansm connected to theslide for shifting the slide towards or from the wheel to select theposition of the center of oscillation.

JOSEPH KLOPAK.

REFERENCES CITED The following references are of record in the le ofthis patent:

UNITED STATES PATENTS Number Name Date 761,350 Barr May 31, 19041,089,455 Beam Mar. 10, 1914

